Pitman



' (NoModeL) v R. S. MITOHELL.

. PITMAN. No. 358,364. Patented Feb. 22, 1887.

' nnummum rlj imm Eli ' lUNiTED i STATES RUFUS S. MITCHELL, OF

PAT NT OFFICE.

BEARDSTOWN, ILLINOIS.

PITMAN.

SPECIFICATION forming part of Letters Patent No. 358,364, dated February 22, 1887.

Application filed May 7, 1886. Serial No. 201,456. (No model.)

To all whom it may concern:

Be it known that I, RUFUS S. MITCHELL, of Beardstown, in the county of Cass and State of Illinois, have invented certain new and useful Improvements in Pitmen; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form part of this specification, in which Figure 1 is an elevation of a pitman embodying my invention. Fig. 2 isavertical section ofthe same. Fig. 3 is a plan view. Figs. 4, 5, and 6 are detail views of the same. Fig. 7 is a front and edge view of a modification. Fig. 8 represents a similar view of another modification of the pitman.

This invention relates to improvements in pitman-rods for sewingmachines and other light machinery; and it consists in the novel construction and arrangement of parts of the pitnian, whereby wear upon the journals of the same, or upon the crank-pins to which the pitman is attached, may be compensated and the pitman always kept in smooth and easy working condition, as will be fully understood from the following description, when taken in connection with the accompanying drawings, and particularly specified in the claims.

A designates the pitman, of suitable size, and having central longitudinal cuts or narrow slots, at, extending from its journals inward; or the pitman may be made in two equal sections, suitably united, the joints between the sections answering the purpose of the slot, the object of the slots a being to admit of lateral adjustment of the journals, as will be hereinafter described. The, outer ends of the .pitman are slotted, as shown at a, the slots being just the width of the diameters of the journals. The inner half of the journal is formed in the pitman, and the outer half on the inher end of a block or traveler, B, which is adapted to enter and fit snugly while moving freely within the slot (1, as shown. The outer ends of the pitman-rod and the block B are made cylindrical, as shown, and are slightly tapered outward, for a purpose hereinafter explained.

C designates metal bands or rings which fit snugly over the outer ends of the pitman and blocks B, and are secured in place by means of bolts or pins 0, which pass through proper diametric openings in the rings and through the ends of the pitman and blocks B. The blocks B are slotted where pins 0 pass through them, so as to permit the blocks free longitudinal movement within the slots a, while preventing their escape therefrom.

D D designate rings or hands placed loosely upon the ends of the pitman and blocks B, to the inner side of rings 0, by which they are kept in place. The adjacent edges of rings 0 and D are provided with a similar number of cam-faces, which act together to spread apart the rings.

The inner smooth edges of rings D engage against pins or studs 12, secured on opposite edges of blocks B, so that when the rings D are turned until their cams engage against the cams onIrings Othebloeks B are forced inward against the arm or crank-pin secured within the journal. I

The rings D may be provided with a milled outer surface to secure a better grasp for the fingers or hand when tightening the same against the rings 0. 7

It is obvious from the foregoing description that any longitudinal wear on the journals of the pitman or wear on the crank-pins secured within the same can be easily compensated by tightening the rings D, as described; and by having the ends of the pitman and blocks conical the rings D, when forced inward by engagement of their cams against those of rings 0, will take up lateral wear of the journals or crank-pins, the slots a or joints between the sections of pitman admitting this lateral ad justment, both lateral and longitudinal compensation being effected by one turn of either ring D.

In Fig. 7 Ihave shown a modification of the adjusting-rings, in this case only one ring he ing used. The ends of the pitman and blocks B are made as before described; but instead of 5 bands 0 D a band, E, having cam-slots e is used, the pins 0 passing through these slots and affording bearings for their cams to act against to effect the desired compensation. Fig. 8 shows another modification, all the parts found useful in some instances; but the firstdescribed construction I deem preferable, as affording greater stability, strength, and a nicer adjustment.

Having described my invention, I claim 1. A pitman-rod provided with a rounded outer end slotted longitudinally from its bearing outward, in combination with a block fitting and moving within the slot, and a camfaeed ring or rings adapted to cause the blocks to compensate wear of the journal-pin in the bearing, substantially as specified.

2. The combinatiomwith a pitman-rod provided with rounded and slotted ends outside of its journals, and having blocks fitted and moving within the slots, of cam-faced rings fitting upon the ends of the pitman and adapted to cause the blocks to compensate wear of the journals, by means substantially as described.

3. The combination, with a pitman-rod having its ends outside of its journal rounded and slotted and provided with blocks fitting wit-bin I the slots, as described, of the rings 0, secured on the ends of the pitman and blocks and provided with cam-faces on their inner edges, and rings D, placed upon the ends of the pitman and blocks at the inner side of rings 0, and provided with cam-faces engaging those of the latter, whereby any wear of the journals or crank-pins within the same can. be compensated, all substantially as specified.

4. The combination, with a pitman-rod having its ends outside of itsjournal made coni cal and slotted, and having blocks B playing within the slots, as described, of rings 0, se-. 

